- Jan 13, 2003
I read that one is only found in higher elevations... I have since forgotten which one. Perhaps the color morph developed to make it less visible to predators at the different elevation?
I'm not damning the crossing out of hand, but I think it should be done with greater understanding of these spiders than we have now, unless we're talking experiments that never leave the "lab". It is not known for sure that P. murinus is just a highly variable species with intergrades all throughout the range...like your E. obsoleta example. If this turns out to be the case, I don't see anything wrong with selective breeding to ephisize certain traits, like vividness of coloration, etc. I'm still not sure if it's a great idea to cross distant populations, consider, for example, crossing the black rat with the everglades.Originally posted by skinheaddave
I'd like to know a lot more about their natural population dynamics before damning crossing between the two colour morphs -- and experimental crossing might go a long way towards interpreting population dynaimcs if they are properly studied.
Mr. Internet,Originally posted by Mister Internet
Interesting thoughts... I read quite a bit about Corn Snake genetics last year, which is a bit different. Basically, you have NO naturally occuring aberrant color morphs (barring albino and mutations) that are self-sustaining. The only localized color morph is the "Okeetee" color morph, which is no more than an extremely brilliant normal coloring/patterning. ALL the "designer" snakes (Butter Cream, Peppermint, Caramel, Charcoal, etc etc) are selective breedings of select mutations. I'm under no delusions that it would be this easy to manipulate T genes, but your questions about environment, locality, and other factors raise interesting possibilities.
Wade,Originally posted by Wade
Cross breeding to see what happens is one thing, but is quite annother to sell or otherwise allow the resulting spiders to enter the trade. If Tom's suggestion is correct, and it's an either-or type thing, then the crossed spiders would end up being identified as whichever parent they look like. If you're a T breeder, you might want to breed the Mombassa (since it's not as common in the hobby as the Usambara), so you breed what you think are pure Mombassas, but when they emerge half the slings are orange! Personally, I'd be pretty PO'd! Also, down the line annother taxonomist may come along and revise the whole thing and want to call the Usambaras a subspecies (subspecies are not popular among T taxonmists at the present time, but that could change), then we are talking hybrids.
Yes and no. There are many different ways of defining and determining what constitutes a species. The one that is in favour now is generally the biological species concept which states, quite simply, that reproductive isolation is the yardstick by which we measure what constitutes a species. There are, however, some provisos attached to the use of such a system. These include the fact that it must be considered under natural conditions and only on a short time scale -- really a snapshot in evolutionary terms. With enough persuasion and interference, there are lots of species which could probably produce fertile offspring. This is not, however a fair indication that they are the same species, as it is not under natural conditions. If, however, it was found that they could not x-breed, then that would constitute evidence of reproductive isolation at the genetic level and thus that speciation had occured.Originally posted by Wade
I believe the resulting spiders may be fertile. My understanding of the rules suggests that, from a taxonomic point of view, this would indicate that these are not seperate species, but simply a single, highly variable species.
Wade,Originally posted by Wade
You are right about the use of the word "hybrid". True hybrids, like your mule example, are generally sterile, correct?
The term would definately not apply to the P. murinus situation, but we often use the term to describe crosses between animals currently recognized as distict species, such as B. smithi and B. vagans. I believe the resulting spiders may be fertile. My understanding of the rules suggests that, from a taxonomic point of view, this would indicate that these are not seperate species, but simply a single, highly variable species. When T people get worked up over hybrids, we're concerned about the fertile crosses (that may not be true hybrids). If they were infertile, like the mule, the experiment would end with that generation and there would be no lasting negative result, because if it can't reproduce, it can't effect the gene pool.
Whew! We've almost beaten this topic to death, yet again. Ahhh, hybrids...
Every time this topic comes up this sort of thing happens, I enjoy it but I can understand a lot of people getting muddled brains because of it.Originally posted by sunnymarcie
..............Sorry if I hijack your thread!.............
It's all yours guys, I got the answer I was looking for.;P
Originally posted by Professor T
You have a slightly different gene pool existing in two geographic races that natural selection produced. Why reverse in a generation what could have taken millions of years to produce?
Adrian,Originally posted by belewfripp
Again from what I understand from what others have said, the problem with IDing Pterinochilus of any species is that over their ranges they show a marked variation. This is noted somewhat in TTKG by Schultz and Schultz. This means that usumbaras and mombasas haven't been geographically segregated into nice, neat population distributions, rather it is quite the opposite. It would be nice to hear from someone who has been to their habitat and could tell us just how closely in proximity different members of this species' color forms live.
Hi,Originally posted by Professor T
It is my understanding that the "usambara" color morph is geographically isolated to the Usambara Mountains in Tanzania.
I think it's been said that males tend to have more yellow and females more reddish and orange.Originally posted by sunnymarcie
Ok a difference in color question makes me wonder.......
Is there a difference in color male vs. female?
Or are there just different phases of color?
The color was the first thing that caught my eye, I do
not want anymore plain brown T's